SX1239IMLTRT Semtech, SX1239IMLTRT Datasheet - Page 46

• Manufacturer Part Number: SX1239IMLTRT
• Description: IC, RF RECEIVER, 1.02GHz, QFN-24
• Manufacturer: Semtech

Specifications of SX1239IMLTRT

• Applications: Wireless Sensor Networks, Automated Meter Reading, Home And Building Automation
• Receiving Current: 16mA
• Data Rate: 300Kbps
• Modulation Type: FSK, OOK
• Sensitivity Dbm: -120dBm
• Rohs Compliant: Yes
• Rf Ic Case Style: QFN
• No. Of Pins: 24
• Sensitivity (dbm): -120dBm
• Supply Voltage Range: 1.8V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / Rohs Status: Supplier Unconfirmed

5.5.2.3. Unlimited Length Packet Format
Unlimited length packet format is selected when bit PacketFormat is set to 0 and PayloadLength is set to 0.
The user can then receive packets of arbitrary length and PayloadLength register is not used in Rx modes for counting the
length of the bytes received. This mode is a replacement for the legacy buffered mode in SX1211/SX1212 transceivers.
The data processing features like Address filtering, Manchester decoding and data dewhitening are not available if the
sync pattern length is set to zero (SyncOn = 0). The CRC detection is also not supported in this mode of the packet
handler. The interrupts like CrcOk & PayloadReady are not available either.
An unlimited length packet shown in is made up of the following fields:
Rev 3 - Jan 2011
ADVANCED COMMUNICATIONS & SENSING
Optional Address byte (Node ID)
Message data
Optional 2-bytes CRC checksum
Preamble (1010...).
Sync word (Network ID).
Optional Address byte (Node ID).
Message data
0 to 65535
Preamble
0 to 65535
Preamble
bytes
bytes
Optional User provided fields which are part of the payload
Message part of the payload
Fields processed and removed in Rx
Optional User provided fields which are part of the payload
Fields processed and removed in Rx
Message part of the payload
0 to 8 bytes
0 to 8 bytes
Sync Word
Sync Word
Figure 30. Unlimited Length Packet Format
Figure 29. Variable Length Packet Format
Address
Length
byte
byte
DC free Data decoding
Address
CRC checksum calculation
byte
Payload
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unlimited length
(min 2 bytes)
DC free Data decoding
Message
Payload
AES Decryption
Up to 255 bytes
Message
2-bytes
CRC
DATASHEET
www.semtech.com
SX1239